1. Field of the Invention
The present invention relates to a differential amplifier having a variable gain.
2. Background of the Invention
Various type of differential amplifiers having an arrangement of the variable gain have been well known. For instance, Japanese Patent Applications published as JP-S61-219208A, JP-S62-245810A, and JP-H01-133403, each disclosed a differential amplifier with the variable gain. However, conventional differential amplifiers showed a subject that the cross point of the output shifted as varied the gain thereof.